Devices and Methods for Treating Valvular Regurgitation

ABSTRACT

A system for treating mitral valve regurgitation includes a tensioning device having a plurality of helical anchors and a tensioning filament. One embodiment of the invention includes a method for attaching a tensioning device to the annulus of a mitral valve in a trans-leaflet configuration, and applying a tension force to the tension filament in order to exert force vectors on the annulus, thereby reshaping the mitral valve annulus so that the coaption of the anterior and posterior leaflets of the mitral is improved during ventricular contraction.

RELATED APPLICATIONS

This application claims the benefit of, and priority to, U.S.Provisional Patent Application 61/045,021 filed on Apr. 15, 2008. Theentirety of that application is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates generally to the treatment of mitral valveregurgitation and particularly to a method and device to improve mitralvalve coaption in a diseased heart.

BACKGROUND

The heart is a four-chambered pump that moves blood efficiently throughthe vascular system. Blood enters the heart through the vena cava andflows into the right atrium. From the right atrium, blood flows throughthe tricuspid valve and into the right ventricle, which then contractsand forces blood through the pulmonic valve and into the lungs.Oxygenated blood returns from the lungs and enters the heart through theleft atrium and passes through the mitral valve into the left ventricle.The left ventricle contracts and pumps blood through the aortic valveinto the aorta and to the vascular system.

The mitral valve consists of two leaflets (anterior and posterior)attached to a fibrous ring or annulus. In a healthy heart, the mitralvalve leaflets close during contraction of the left ventricle andprevent blood from flowing back into the left atrium. Due to variouscardiac diseases, however, the mitral valve annulus may become distendedcausing the leaflets to remain partially open during ventricularcontraction and thus allow regurgitation of blood into the left atrium.This results in reduced ejection volume from the left ventricle, causingthe left ventricle to compensate with a larger stroke volume. However,the increased workload eventually results in dilation and hypertrophy ofthe left ventricle, further enlarging and distorting the shape of themitral valve. If left untreated, the condition may result in cardiacinsufficiency, ventricular failure, and ultimately death.

It is common medical practice to treat mitral valve regurgitation byeither valve replacement or repair. Valve replacement involves anopen-heart surgical procedure in which the patient's mitral valve isremoved and replaced with an artificial valve. This is a complex,invasive surgical procedure with the potential for many complicationsand a long recovery period.

Mitral valve repair includes a variety of procedures to repair orreshape the leaflets to improve closure of the valve during ventricularcontraction. If the mitral valve annulus has become distended, afrequent repair procedure involves implanting an annuloplasty ring onthe mitral valve annulus. The annuloplasty ring generally has a smallerdiameter than the annulus, and when sutured to the annulus theannuloplasty ring draws the annulus into a smaller configuration,bringing the mitral valve leaflets closer together, and allowingimproved closure during ventricular contraction. Annuloplasty rings maybe rigid, flexible or a combination, having both rigid and flexiblesegments. Rigid annuloplasty rings have the disadvantage of causing themitral valve annulus to be rigid and unable to flex in response to thecontractions of the ventricle, thus inhibiting the normal, threedimensional movement of the mitral valve that is required for it tofunction optimally. Flexible annuloplasty rings are frequently made ofDacron fabric and must be sewn to the annular ring with a line ofsutures. This eventually leads to scar tissue formation and loss offlexibility and function of the mitral valve. Similarly, combinationrings must generally be sutured in place and also cause scar tissueformation and loss of mitral valve flexibility and function.

Another approach to treating mitral valve regurgitation requires aflexible elongated device that is inserted into the coronary sinus andadapts to the shape of the coronary sinus. The device then undergoes achange that causes it to assume a reduced radius of curvature and, as aresult, causes the radius of curvature of the coronary sinus and thecircumference of the mitral annulus to be reduced. While likely to beeffective for modest changes in the size or shape of the mitral annulus,this device may cause significant tissue compression in patientsrequiring a larger change in the configuration of the mitral annulus.Alternatively, the coronary sinus in a particular individual may notwrap around the heart far enough or may not be in an optimum position toallow effective encircling of the mitral valve, making this treatmentineffective. Furthermore, leaving a device in the coronary sinus mayresult in formation and breaking off of thrombus that may pass into theright atrium, right ventricle, and ultimately the lungs causing apulmonary embolism. Another disadvantage is that the coronary sinus istypically used for placement of a pacing lead, which may be precludedwith the placement of the prosthesis in the coronary sinus.

It would be desirable, therefore to provide a method and device forreducing mitral valve regurgitation that would use minimally invasivesurgical techniques, but would overcome the limitations anddisadvantages inherent in the devices described above.

BRIEF SUMMARY OF THE INVENTION

One aspect of the invention provides a system for treating mitral valveregurgitation comprising a delivery catheter and a tensioning device.The tensioning device comprises a plurality of helical anchors and atension filament. The anchors are deployed from a delivery catheter suchthat they are implanted in the annulus of the mitral valve, and thetension filament is adjusted so that the shape of the annulus is changedin order to achieve coaption of the mitral valve leaflets.

Another aspect of the invention provides a method for treating mitralvalve regurgitation and includes preloading a tensioning device into aninternal lumen of an elongated delivery catheter or delivery member. Thetensioning device comprises a plurality of helical anchors, a tensionfilament, and at least one locking device to secure the tensioningdevice after the shape of a mitral valve has been changed. The methodfurther comprises deploying the tensioning device from the catheteradjacent to the mitral valve and embedding the anchors into the annulussuch that the tension filament extends through the anchors. Next, atension force is applied to the tension filament, causing the posteriorand anterior sides of the mitral valve annulus to be drawn closer toeach other.

The present invention is illustrated by the accompanying drawings ofvarious embodiments and the detailed description given below. Thedrawings should not be taken to limit the invention to the specificembodiments, but are for explanation and understanding. The detaileddescription and drawings are merely illustrative of the invention ratherthan limiting, the scope of the invention being defined by the appendedclaims and equivalents thereof. The drawings are not to scale. Theforegoing aspects and other attendant advantages of the presentinvention will become more readily appreciated by the detaileddescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a plan view of a heart showing the location of the heartvalves;

FIG. 2 shows one embodiment of a tensioning device attached to a mitralvalve annulus according to the current invention;

FIG. 3 shows another embodiment of a tensioning device attached to amitral valve annulus according to the current invention;

FIGS. 4A and 4B show a helical anchor for a tensioning device accordingto the current invention;

FIG. 5 shows a system for modifying the shape of a heart valve annulusaccording to the current invention;

FIGS. 6A and 6B show an embodiment of an annulus modification systemaccording to the current invention

FIG. 7 illustrates the attachment of helical anchors to an helicalanchor driver according to the current invention;

FIGS. 8A and 8B illustrate an embodiment of locking devices used fortensioning devices according to the current invention;

FIGS. 9 to 11 illustrate a minimally invasive surgical method forimplanting tensioning devices to treat mitral regurgitation according tothe current invention;

FIGS. 12 and 13 illustrate a catheter based method for implantingtensioning devices to treat mitral regurgitation according to thecurrent invention; and

FIG. 14 is a flow chart showing one embodiment of a method forimplanting a tensioning device according to the current invention.

DETAILED DESCRIPTION

The invention will now be described by reference to the figures whereinlike numbers refer to like structures. The terms “distal” and “proximal”are used herein with reference to the treating clinician during the useof the catheter system; “Distal” indicates an apparatus portion distantfrom, or a direction away from the clinician and “proximal” indicates anapparatus portion near to, or a direction towards the clinician.

The current invention discloses devices and methods for treatingregurgitation in cardiac valves. While these devices and methods aredescribed below in terms of being used to treat mitral valveregurgitation, it will be apparent to those skilled in the art that thedevices could be used on other cardiac valves, also. Tensioning devicesof the current invention comprise helical anchors, at least one tensionfilament, and locks. The tensioning devices are used to modify the shapeof heart valves for treating valvular regurgitation. The systems of thecurrent invention comprise the tensioning devices and the deliverymembers for placing the tensioning devices adjacent a heart valveannulus. The devices and systems of the current invention can bedelivered to a patient's valve annulus via catheter through thepatient's vasculature, via a tubular access port (or other port) as partof a minimally invasive surgical approach, or via an open heart surgicaldelivery.

Referring to the drawings, FIG. 1 shows a plan view of a cross-sectionof a heart 1 having tricuspid valve 2 and tricuspid valve annulus 3.Mitral valve 4 is adjacent mitral valve annulus 5. Mitral valve 4 is abicuspid valve having anterior cusp 7 and posterior cusp 6. Anteriorcusp 7 and posterior cusp 6 are often referred to, respectively, as theanterior and posterior leaflets. Also shown in the figure are theposterior commisure 17 and the anterior commisure 18.

FIG. 2 shows one embodiment of a tensioning device 200, made inaccordance with the present invention, attached to a mitral valveannulus 5. Tensioning device 200 comprises three helical anchors 245A,245B, and 245C, implanted along the posterior portion of the annulusbetween the posterior commisure and the anterior commisure. Tensioningdevice 200 further comprises a pair of helical anchors 245D and 245Eimplanted along the anterior portion of the valve annulus between theleft and right trigones. A tension filament 250 is disposed in the innerchannels of the helical anchors. Tensioning device 200 comprises atrans-leaflet tensioning device whereby tension filament 250 isconfigured to cross from one leaflet to another in a generally zig-zagpattern. In one embodiment shown in FIG. 2, tension filament 250comprises a plurality of trans-leaflet portions 253A to 253D. Each ofthe trans-leaflet portions 253A to 253D extend from a helical anchorimplanted in the anterior leaflet 7 to another helical anchor implantedin the posterior leaflet 6. In this embodiment, trans-leaflet portion253A extends from helical anchor 245A to helical anchor 245E;trans-leaflet portion 253B extends from helical anchor 245E to helicalanchor 245B; trans-leaflet portion 253C extends from helical anchor 245Bto helical anchor 245D and trans-leaflet portion 253D extends fromhelical anchor 245D to helical anchor 245C. In this embodiment, a firstfilament lock 255A is located at the end of the tension filament thatpasses through the helical anchor 245A that is adjacent to the anteriorcommisure and a second filament lock 255B is located at the end of thetension filament that passes through the helical anchor 245C that isadjacent to the posterior commisure. The force vectors resulting fromtension on filament 250 are exerted through anchors 245A to 245E andcause the shape of mitral valve 5 to change, which in turn, draws thevalve leaflets closer together and improves coaption. The direction andmagnitude of the force vectors exerted at each anchor are determined byplacement of the anchors along the annulus and the amount of tensionplaced on the filament.

Those with ordinary skill in the art will appreciate that the number ofhelical anchors implanted into the valve annulus may vary depending on aparticular application. In at least one embodiment of the invention,fewer than five helical anchors are implanted in the valve annulus todraw the two sides of the annulus closer together. In another embodimentof the invention, more than five anchors are implanted in the valveannulus to draw the sides of the annulus closer together. In oneembodiment, the number of implanted helical anchors is as few as threeand as many as seven or more. The number of helical anchors implantedinto the valve annulus may be determined by such factors as, but notlimited to, the size of the valve annulus, the size of the helicalanchors, the degree of valve regurgitation to be corrected and theamount of tension required to provide coaption.

FIG. 3 illustrates another embodiment of a tensioning device 300 inaccordance with the present invention. In this embodiment, system 300includes three helical anchors 345A to 345C and tensioning filament 350.Tensioning filament 350 includes two trans-leaflet portions, portion353A extending from helical anchor 345A to helical anchor 345B andportion 353B extending from helical anchor 345B to helical anchor 345C.System 300 further includes a first filament lock 355A located at theend of the tension filament that passes through helical anchor 345A anda second filament lock 355B located at the end of the tension filamentthat passes through helical anchor 345C.

As described above, the tensioning devices of the current invention areattached to the annulus of a mitral valve using helical anchors. In oneembodiment, the tensioning devices are delivered to, and implanted in, abeating heart using a minimally invasive surgical technique. In anotherembodiment, the tensioning devices are delivered and implanted via acatheter based delivery system that accesses the valve through thevascular system. Where devices are delivered using minimally invasivesurgical procedures, the delivery instruments can be inserted throughthe wall of the atrium at a location directly adjacent to the posteriorcommisure. If the devices are delivered to the atrium via catheter, thecatheter can enter the atrium through an opening created in the septalwall between the left and right atrium. The devices of the invention canalso be implanted in the valves of a temporarily stopped heart and inone embodiment the device is delivered via open heart surgery. Devices,systems, and methods for changing the shape of the annulus of a cardiacvalve using devices having helical anchors are described in UnitedStates Patent Applications having the following publication numbers, allof which are incorporated herein by reference thereto: US 2007/0244557;US 2007/0244553; US 2007/0244554; US 2007/0244555; and US 2007/0244556.

Referring again to the drawings, FIGS. 4A through 8B illustrate thecomponents of an embodiment of an annulus modification system formodifying a heart valve according to the current invention. Referringfirst to FIGS. 4A and 4B, there is shown a helical anchor 445 for atensioning device according to the current invention. Helical anchor 445comprises an elongate coiled member having a tissue penetrating tip 446at a distal end and a proximal end 447 that is operably connected to ahelical anchor driver.

The coils of the helical anchor 445 define a structure having agenerally circular shape and a tip 446 that extends on a tangent awayfrom the circular perimeter of the helical anchor. Angling the sharpenedtip 446 away from the exterior perimeter of the helical anchor makes iteasier for the tip to penetrate a valve annulus when the helical anchoris being rotated out of a delivery member and along an anchor guide. Insome embodiments, the length L of the sharpened tip portion is in therange of 0.045 inches to 0.065 inches. One embodiment of a helicalanchor has a tip length greater than 0.065 inches, another embodimenthas a tip length less than 0.045 inches, and one embodiment of a helicalanchor according to the current invention has a tip length of 0.055inches.

Helical anchor 445 comprises a biocompatible metallic or polymericmaterial having suitable resiliency. In one embodiment, helical anchor445 comprises stainless steel, in another embodiment, the helical anchorcomprises 35NLT, and in yet another embodiment the helical anchorcomprises MP35N. The diameter of the metallic or polymeric member thatis coiled to make the helical anchor can vary based on such factors as,but not limited to, the desired flexibility, the size of the annulus,and the delivery method. Some embodiments include helical anchors madefrom wires with diameters in a range of 0.017 inches-0.025 inches. Oneembodiment is made from a material with a diameter smaller than 0.017inches, another embodiment is made from a material with a diameterlarger than 0.025 inches, and yet another embodiment is made from amaterial having a diameter of 0.02 inches.

The coils of the helical anchor define an inner channel 444 for passageof a tension filament. The helical anchor has an outer diameter definingthe exterior of the helical anchor and an inner diameter defining thechannel or lumen through the helical anchor. Some embodiments of theinvention include helical anchors having inner channel diameters in therange of 0.10 inches-0.20 inches. One embodiment includes a helicalanchor with an inner channel diameter smaller than 0.10 inches, anotherembodiment has a helical anchor with an inner channel diameter largerthan 0.200 inches, and yet another embodiment has a helical anchor withan inner channel diameter of 0.11 inches. Outer diameters for thehelical anchors are in the range of 0.150 inches-0.250 inches. Oneembodiment includes a helical anchor with an outer diameter smaller than0.150 inches, another embodiment has a helical anchor with an outerdiameter larger than 0.250 inches, and yet another embodiment has ahelical anchor with an outer diameter of 0.150 inches.

The distance between each coil defines the coil pitch, and the pitch canalso be expressed as the number of coils per inch. The number of coilsper inch for the helical anchors of the current invention can vary basedon the desired degree of flexibility and resiliency. Some embodimentsinclude helical anchors having coils per inch in the range of 10 to 20.One embodiment of a helical anchor has less than 10 coils per inch, oneembodiment of a helical anchor has more than 20 coils per inch, and oneembodiment of a helical anchor according to the current invention has 12coils per inch. An additional embodiment of the current inventionincludes helical anchors having 14 coils per inch.

In addition to the pitch, the length of the helical anchors of thevarious embodiments of the invention can vary based on the size of apatient's valve annulus and the number and location of helical anchorsneeded to modify the shape of the annulus. In one embodiment of theinvention, multiple helical anchors are implanted.

Some embodiments of the invention include helical anchors having alength in the range of 0.20 inches to 0.5 inches. At least oneembodiment has at least one helical anchor longer than 0.5 inches andanother embodiment has at least one helical anchor shorter than 0.20inches. One embodiment of the invention uses a plurality of helicalanchors having the same length to modify the shape of a heart valveannulus. Another embodiment of the invention uses a plurality of helicalanchors where not all of the helical anchors have the same length.

The flexibility of the helical anchor can be controlled by the diameterof the wire or other material used to make the helical anchor and thenumber of coils per inch. As will be described further below, a tensionfilament will be placed through the inner channel of one or more helicalanchors that are implanted along a heart valve annulus. The tensionfilament will then be manipulated to exert a force on the helicalanchors to draw the two sides of the annulus closer together, therebymodifying the shape of the valve annulus and improving coaption of thevalve leaflets.

Helical anchors 445 comprise a plurality of individual coils. Theplurality of coils forms a generally cylindrical inner channel 444 thatcan accommodate an anchor guide and through which a portion of a tensionfilament will be disposed. In operation, the inner channel diameter, thecoil pitch and the length of the tip 446 of the helical anchor may bedetermined to provide a specific depth of penetration of the helicalanchor 445 as it is threaded along the valve annulus.

FIG. 5 shows an embodiment of a system 500 for changing the shape of avalve annulus according to the current invention. This embodimentcomprises an elongated generally tubular delivery member 520 having ahandle 521 and a handle cap 522 on the proximal end of the deliverymember 520. The distal end of the delivery member 520 includes an anchorguide 525 and a distal opening 524 of the driver lumen that communicatesthrough the length of the delivery member. Anchor guide 525 isconfigured to conform to the shape of at least a portion of the valveannulus when the anchor guide is placed next to a valve annulus at thetreatment site.

An elongated helical anchor driver 530 includes a driver knob 531 on theproximal end of the driver and a threaded portion 537 adjacent the knob.A distal portion 535 of the driver is connected to a helical anchor 545.The system also includes a flexible elongated tension filament 550having a first end 551 and a second end 552. The tension filament 550 isdelivered to the treatment site in a looped configuration with first andsecond ends extending outside the patient's body during the implantationprocedure.

To use the system, the first end 551 of the tension filament 550 isthreaded into a tension filament lumen 534 at the proximal end of thedriver and out through an inner channel of the helical anchor 545. Thetension filament is then threaded into the driver lumen and into atension filament lumen (not shown) in the anchor guide 525. The tensionfilament exits the end of the anchor guide and is routed back up throughthe driver lumen and exits the handle 521 through another tensionfilament lumen (not shown). For the delivery of each successive anchorof the system, the ends of the tension filament can be threaded throughadditional drivers, helical anchors and/or delivery members based on themethod of delivery and where the new helical anchor will be implantedrelative to the preceding helical anchor.

Referring to FIG. 6A, the driver 530 is inserted into the driver lumenof the delivery member 520 and advanced until the threaded portion 537makes contact with a complementary threaded portion (not shown) on theinterior of the delivery member handle 521. When the driver has beenadvanced to the point where the threaded portion on the driver makescontact with the threaded portion on the handle, the helical anchor 545will be located adjacent to the anchor guide 525. The anchor guide 525would then be aligned with a valve annulus and placed on the annulus inthe desire location for implanting the helical anchor such that theanchor guide is laying directly on the valve annulus and directlyadjacent the wall of the heart chamber. The anchor guide will be shapedso that it conforms to the shape of the annulus at the point of desiredanchor implantation. In at least one embodiment, the same anchor guidecan be used for implanting all helical anchors. In at least oneembodiment of the invention, multiple anchor guides are used forimplanting the helical anchors. In at least one embodiment, each of themultiple anchor guides used for implanting a plurality of helicalanchors is shaped to correspond to the geometry of a specific portion ofthe valve annulus to be treated.

Once anchor guide 525 is in the correct position, the driver is rotatedvia handle 531 and the anchor is rotated into the valve annulus. In atleast one embodiment, the rotation occurs such that the tip of theanchor is rotated toward the wall of the heart as the guide rests on thetop of the annulus and the system is viewed from above. In at least oneother embodiment, the rotation occurs such that the tip of the anchor isrotated away from the wall of the heart as the guide rests on the top ofthe annulus and the system is viewed from above.

In at least one embodiment, the delivery member is left inside of apatient's body and the driver is withdrawn from the delivery member foreach successive helical anchor. The tension filament is threaded into anadditional helical anchor and driver. The new driver is then insertedinto the delivery member and advanced so that the helical anchor is atthe distal opening in the delivery member. The anchor guide is thenmanipulated so that it is placed on the portion of the valve annuluswhere the additional helical anchor is desired, and the helical anchoris implanted as described above. The other helical anchors can beimplanted using the same delivery member, or the delivery member can bewithdrawn and the other helical anchors implanted using additionaldelivery members and drivers as described above.

Referring now to FIG. 6B, the driver knob 531 is rotated so that thethreaded portion 537 on the driver is screwed into the complementarythreaded portion of the delivery member 520. As the driver is threadedinto the delivery member, the distal portion of the driver rotates andmoves toward the distal opening 524 of the delivery member until thedistal end of the helical anchor is extended from the delivery memberand the distal end is rotated into and out of the valve annulus whilethe helical anchor moves along the anchor guide.

In some embodiments of the systems of the current invention, the helicalanchor is engaged to the distal tip of the driver and the driver andhelical anchor are placed in the delivery member such that the anchorguide is already in the inner channel of the helical anchor. In otherembodiments, the extended distal tip of the helical anchor catches theanchor guide, as the distal end of the helical anchor extends from thedistal opening of the delivery member, and the helical anchor is rotatedonto and along the delivery guide and into the annulus as the driver isthreaded into the delivery member.

Once the helical anchor is implanted, the anchor guide is withdrawn intothe delivery member. After the anchor guide is removed from the innerchannel of the helical anchor, a portion of the tension filament remainsdisposed in the helical anchor such that one end of the tension filamentextends from the distal end of the helical anchor and the other end ofthe tension filament extends from the proximal end of the helicalanchor.

The tension filament slides freely through the tension filament lumensor other portions of the delivery member and driver while they are beingwithdrawn, and it can be completely removed from those portions of thesystem such that the ends extend outside of a patient's body while aportion of the tension filament is disposed in the inner channel of thehelical anchor implanted in the patient's heart valve annulus.

The components of the system can be made from any suitable biocompatiblematerial. Based on the delivery method, the delivery members can be madeof flexible, biocompatible polymeric material such as, but not limitedto, polyurethane, polyethylene, nylon and polytetrafluoroethylene(PTFE); or they can be made can be made from rigid plastics or metalssuch as stainless steel or other suitable metal. The delivery memberscan also be made from a combination of two or more of these materials.

The drivers can also be made from flexible, biocompatible polymericmaterial such as, but not limited to, polyurethane, nylon,polytetrafluoroethylene (PTFE) and polyethylene. Portions of the drivercan be made from rigid plastics or metals such as stainless steel orother suitable metals as long as the distal portion of the driver ismade from a flexible material that will allow it to negotiate curvedportions of the delivery member. In one embodiment, the proximal portionof the driver is a braided member formed from a plurality of metallicfilaments. In other embodiments, the drivers can include portions madefrom polymeric filaments or a combination of metallic and polymericfilaments. The materials used to manufacture the driver may be chosen toprovide a determined flexibility or stiffness along the length of thedriver.

The lumens of the delivery members and drivers of the current inventioncan be coated with a lubricious material such as silicone,polytetrafluroethylene (PTFE), or a hydrophilic coating. The lubriciousinterior surface of a delivery member facilitates the longitudinalmovement of a driver.

The anchor guides can be made from a suitable biocompatible metallic orpolymeric material or combinations thereof. The anchor guides of thecurrent invention can be made from a flexible material, but the materialmust be hard enough to resist penetration by the sharpened distal end ofa helical anchor. In one embodiment of the invention, the anchor guideis made from stainless steel. In another embodiment, the anchor guide ismade from a shape memory material that assumes a predetermined shapeupon exiting delivery member 520. In one embodiment of the invention,the tubular delivery member and the anchor guide are formed as a unitarypiece from a biocompatible material. In other embodiments, the deliverymembers and anchor guides are fashioned as separate pieces that arejoined together by, for example, adhesive, welding or any other mannerknown in the art.

The tension filaments of the current invention are elongated, flexiblefilaments of any suitable biocompatible material. In one embodiment, thetension filament comprises a monofilament. In other embodiments thetension filaments may comprise a braid of a plurality of filaments ofthe same material or of filaments from different materials. Still otherembodiments of tension filaments comprise a braided sheath with a singlefilament core, or a braided sheath with a braided core. The tensionfilaments may be composed of biocompatible material such as, but notlimited to, nylon or polyester.

The tension filaments may be constructed from material that will notstretch or it may be pre-stressed to prevent the tension filament fromelongating after the annuloplasty devices of the current invention areimplanted in a heart valve annulus. In one embodiment, the tensionfilament is made from a pre-stretched ultra-high-molecular-weightpolyethylene. Various embodiments of the invention include tensionfilaments having diameters in the range of 0.015 inches and 0.050 inchesin diameter. In one embodiment of the invention the tension filament hasa diameter smaller than 0.015 inches and in another embodiment of theinvention the tension filament has a diameter larger than 0.050 inches.One embodiment of the invention has a tension filament with a diameterof 0.020 inches.

FIG. 7 illustrates another embodiment of a release mechanism accordingto the current invention. The helical anchor 545 has a proximal end 546with a driver portion 547 that extends straight in a proximal directionfrom the helical anchor. The distal tip 535 of the driver has a hole 536for placement of the driver portion of the helical anchor such that thehelical anchor will fit snugly into the driver during implantation ofthe helical anchor. Once the helical anchor is implanted, the driver anddelivery member are pulled away from the proximal end of the helicalanchor and the straight driver portion of the proximal end is pulledfrom the hole in the distal tip of the driver. In some embodiments ofthe current invention, the length of the straight driver portion of thehelical anchor can vary from 0.05 inches to 0.25 inches. Someembodiments of the current invention have helical anchors with straightdriver portions that are longer than 0.25 inches, other embodiments ofthe current invention have helical anchors with straight driver portionsthat are shorter than 0.05 inches, and one embodiment of a helicalanchor according to the current invention has a helical anchor with astraight driver portion of 0.10 inches.

In some embodiments of the current invention, the driver can be a hollowmember having either a tension filament lumen or an anchor guide lumencommunicating through its length. The helical anchor connections shownin FIG. 5 will work equally as well for tubular driver members as theywill for non-tubular driver members.

Referring now to FIGS. 8A and 8B, there can be seen a locking device 800according to the current invention. Locking device 800 comprises a stopmember 855 and a lock member 856. Stop member 855 has a size and shapethat will prevent the stop member from entering the inner channel of ahelical anchor. In some embodiments of the invention, the stop member855 will be smaller than the outer diameter of a helical anchor butlarger than the diameter of the inner channel. This will allow the stopmember to be delivered through a delivery member or guide catheter.

Stop member 855 has at least one lumen communicating through the stopmember. In the depicted embodiment, a lock member 856 has a lumencommunicating through a proximal end there of such that the lock membercan be placed on the filament 850 and slide along the length of thefilament. The lock member 856 has a first end and a second end with aplurality of integral legs 857 that extend radially at an angle from thelock member. The legs of the lock member each have a slight lip 859 thatwill prevent the second end of the lock member from being completelyinserted into the stop member.

The lock member is made from material having suitable flexibility toallow the legs to compress radially inward when the first end of thelock member is pushed or otherwise moved into the lumen of the stopmember. The lumen of the stop member is sized such that when the lockmember is inserted into the stop member, the legs of the lock memberwill be radially compressed against the tension filament. The legs ofthe lock member are sized and configured such that when the lock memberis compressed inside the stop member, the tension filament is secured bythe legs and the filament can not slide through the lock member.

FIG. 8B shows that as the lock member is pushed (in the direction of thearrows) along the tension filament 850, it is pushed into the stopmember. Once the lock member has entered the stop member, it cannot moveproximally along the tension filament in the direction of the arrows.

Once the anchors are planted in a valve annulus, a stop member and thena lock member are placed on each end of the tension filament. In oneembodiment, the lock member is pushed into the stop member on one end ofthe filament outside of a patient's body and then the other end of thefilament is pulled until the locking device is directly adjacent one ofthe helical anchors. A desired tension force is then applied to thetension filament. The force is maintained while the stop member and lockmember on the other end of the tension filament are pushed along thefilament such that the stop member makes contact with an implantedanchor and cannot move any further along the filament. The lock memberis then pushed into the stop member to secure the tension filament suchthat the filament is under constant tension. The tension filament isthen trimmed so that no unnecessary free ends of the filament extendbeyond the locking devices.

Returning to FIG. 2, FIG. 2 shows a tensioning device of the currentinvention attached to a mitral valve annulus. Tension filament 250 isdisposed in the inner channels of the helical anchors. In oneembodiment, lock member 255A and 255B comprise a lock member such aslock device 800 illustrated in FIGS. 8A and 8B.

The tensioning device is delivered to a location adjacent the valveannulus using approaches described below. Once the delivery member islocated at a position adjacent the valve annulus, the anchors arerotated into the valve annulus in the manner described above. Unless theprocedure is being performed as an open heart procedure where thetension filament can be threaded through the anchors after implantation,the anchors must be implanted in the same order as the filament isrouted through the anchors. Using the example of FIG. 2, the helicalanchors can be implanted in alphabetical order 245A through 245E or theycan be implanted in reverse alphabetical order. In one embodiment of theinvention, the helical anchors are implanted so that the tensionfilament is threaded in to cross the valve from one valve leaflet toanother valve leaflet in a zig-zag or generally “V” shaped pattern asillustrated in FIGS. 2 and 3, respectively. Once the anchors areimplanted, the locking devices are attached to the filament as describedabove.

In at least one embodiment of the invention, a bead or similar device isattached to one end of the filament instead of a locking device such aslocking device 800. The bead is then drawn tight against one of theanchors 245A or 245E, tension is applied and a locking device is placedagainst the other anchor of 2645A or 2645E as described above. The twosides of the annulus are then drawn closer together such that the shapeof the annulus is changed and coaption of the valve leaflets isimproved.

One exemplary method that can be used for accessing a patient's heartvia minimally invasive surgical procedures to treat mitral regurgitationgenerally can start with intubating a patient with a double-lumenendobronchial tube that allows selective ventilation or deflation of theright and left lungs. The left lung is deflated, thereby helping toprovide access to the surface of the heart. The patient is rotatedapproximately 30 degrees with the left side facing upwardly. The leftarm is placed below and behind the patient so as not to interfere withtool manipulation during the procedure. While port positions depend to alarge extent on heart size and position, in general a seventh and fifthspace mid (to posterior) axillary port for tools and a third spaceanterior axillary port for the scope is preferable. A variety ofendoscopes or thoracoscopes may be used including a 30-degree offsetviewing scope or a straight ahead viewing scope. In general, short 10 to12 mm ports are sufficient. Alternatively, a soft 20 mm port with anoval cross-section sometimes allows for two tools in the port withoutcompromising patient morbidity.

In one embodiment of the present invention, passages are made through apatient's skin into the thoracic cavity. The passages may be formed byemploying one-piece rods or trocars of prescribed diameters and lengthsthat are advanced through body tissue to form the passage, which aresubsequently removed so that other instruments can be advanced throughthe passage. The passage may instead be formed by employing two-piecetrocars that comprise a tubular outer sleeve, which is sometimesreferred to as a port or cannula or as the tubular access sleeve itself,having a sleeve access lumen extending between lumen end openings at thesleeve proximal end and sleeve distal end. The two-piece trocar canfurther include an inner puncture core or rod that fits within thesleeve access lumen. The inner puncture rod typically has a tissuepenetrating distal end that extends distally from the sleeve distal endwhen the inner puncture rod is fitted into the sleeve access lumen foruse. The two-piece trocar can be assembled and advanced as a unitthrough body tissue, and then the inner puncture rod is removed, therebyleaving the tubular access sleeve in place to maintain a fixed diameterpassage through the tissue for use by other instruments.

In one embodiment, a tubular access sleeve is placed through a passagethat is made as described above in the chest wall of a patient. Theselection of the exact location of the passage is dependent upon apatient's particular anatomy. A further conventional tubular accesssleeve can be placed in a different passage that is also made in thechest wall of patient.

In accordance with one method used in the invention, the patient's leftlung is deflated to allow unobstructed observation of the pericardiumemploying a thoracoscope or other imaging device that is insertedthrough a sleeve lumen of a tubular access sleeve. The thoracoscope orother imaging device may have its own light source for illuminating thesurgical field.

A thoracoscope can then be inserted into the lumen of a tubular accesssleeve to permit wide angle observation of the thoracic cavity by asurgeon directly through an eyepiece or indirectly through incorporationof a miniaturized image capture device (e.g., a digital camera) at thedistal end of the thoracoscope or optically coupled to the eyepiece thatis in turn coupled to an external video monitor. The thoracoscope mayalso incorporate a light source for illuminating the cavity with visiblelight so that the epicardial surface can be visualized. The thoracoscopemay be used to directly visualize the thoracic cavity and obtain a leftlateral view of the pericardial sac or pericardium over the heart.

The elongated access sleeve provides an access sleeve lumen, enablingintroduction of the distal end of a pericardial access tool. The tubularaccess sleeve and the pericardial access tool are employed to create anincision in the pericardial sac so that the clinician can view andaccess the left free wall of the heart. After the clinician gains accessto the heart, a continuous circular suture (commonly know and referredto herein as a purse string suture) is placed in the free wall of theleft atrium at a location near the commisure of the mitral valve, andabove the coronary sinus. The wall is then punctured inside theperimeter of the suture. The wall can be punctured using a puncturedevice, or the distal end of the delivery members described herein canbe used to puncture the wall.

The distal end of a first delivery member can then be advanced throughthe elongated access sleeve, through the puncture formed through themyocardium, and placed against the mitral valve annulus. At least afirst anchor of a tensioning device for treating mitral regurgitationcan then be implanted. Subsequent anchors can then be implanted usingadditional delivery devices or additional drivers in the same deliverydevice, tension is applied, and the device is secured, all as describedabove. The delivery member is then withdrawn and the purse string istightened to close the puncture. The lung can then be inflated, theinstruments withdrawn from the patient, and all openings closed. Theprocedure outside of the heart can be viewed through a scope asdisclosed above, and the procedure inside the heart can be visualizedand imaged using fluoroscopy, echocardiography, ultrasound, EM imaging,other suitable means of visualization/imaging, or combinations of theaforementioned visualization methods. Visualization techniques may alsobe used to map the heart prior to beginning the minimally invasiveprocedure. Mapping the heart provides details as to the size and shapeof the valve annulus to be treated and the extent of deformation of thevalve, itself.

FIGS. 9, 10, and 11 illustrate an exemplary placement of deliverymembers of the current invention inside the heart using a minimallyinvasive surgical approach. FIGS. 9 and 10 are illustrations showingcross-sectional views of a heart 1 having tricuspid valve 2 andtricuspid valve annulus 3. Mitral valve 4 is adjacent mitral valveannulus 5. Mitral valve 4 is a bicuspid valve having anterior cusp 7 andposterior cusp 6. Anterior cusp 7 and posterior cusp 6 are oftenreferred to, respectively, as the anterior and posterior leaflets. Alsoshown in the figure are the posterior commisure 17 and the anteriorcommisure 18. A purse string suture has been placed in the heart and thewall is punctured (as described above) at a location 995 in the atriumwall that is adjacent the posterior commisure 17 of the posterior andanterior cusp and above the coronary sinus. An elongated, generallytubular tensioning device delivery member can then be placed into theheart and positioned on the valve annulus for implantation of atensioning device.

Referring particularly to FIG. 11, the location of the puncture site1195 is visible inside of the purse string suture 1197 (the free ends1198 of the which are visible in the figure), and a portion of adelivery member 1130 is illustrated for delivering a tensioning deviceto the posterior portion of a mitral valve annulus. A tensioning device,such as tensioning device 200 and 300, can them be placed in the valveannulus.

FIGS. 12 and 13 illustrate a catheter based approach for implanting atensioning device. FIG. 12 is a longitudinal cross-sectional view ofheart 1 having left atrium 10, left ventricle 11, right atrium 12, rightventricle 13, mitral valve 4, mitral valve annulus 5, tricuspid valve 2and tricuspid valve annulus 3. An elongated delivery catheter 1230having a tensioning device with helical anchors according to the currentinvention is shown with the distal end of the delivery catheter in theleft atrium. When using a catheter based method for implanting atensioning device, an elongate element (not shown), such as a guidecatheter, having a lumen is first installed to provide a path for thetensioning device delivery catheter 1230 from the exterior of thepatient to the left atrium. The tensioning device delivery catheter 1230can then be advanced through the lumen so that the tensioning device canbe implanted in a mitral valve annulus.

The device used for modifying the shape of the annulus is deliveredusing a catheter via the transeptal approach through the vena cava. Theelongate element is inserted through the femoral vein into the commoniliac vein, through the inferior vena cava into the right atrium 12. Thetranseptal wall 14 between the right atrium 12 and left atrium 10 isthen punctured (preferably at the fossa ovalis) with a guide wire orother puncturing device. In one embodiment of the invention, aBrockenbrough® needle system as is currently known in the art can beused to puncture the septum.

Regardless of the method used to puncture the septum, the distal end ofthe catheter is advanced into the left atrium and the anchor guide 1225is positioned adjacent the mitral valve annulus 5, as shown in FIG. 13.The tensioning device can then be advanced through the lumen of theelongate element to the mitral valve 4 for implantation into the mitralvalve annulus 5. The anchor guide and helical anchor are advanced androtated into the annulus.

Those skilled in the art will appreciate that alternative paths to gainaccess to the left atrium are available. For example, another possiblepath would be through the radial vein into the brachial vein, throughthe subclavian vein, through the superior vena cava into the rightatrium, and then transeptally into the left atrium. Yet another possiblepath would be through the femoral artery into the aorta, through theaortic valve into the left ventricle, and then retrograde through themitral valve into the left atrium.

FIG. 14 is a flowchart illustrating one embodiment of a method 1400 tomodify the shape of valve annulus according to the current invention.Method 1400 begins at Block 1410. To practice the current invention, aclinician delivers a tensioning device to a location adjacent a valveannulus (Block 1420). The helical anchors are then implanted in atrans-leaflet configuration alternating from implanting an anchor on theanterior or posterior side of the annulus to an anchor on the oppositeside of the annulus such that the elongated tension member crosses themitral valve each time it is routed through a helical anchor subsequentto the previous helical anchor that the elongated tension member isrouted through (Block 1430). The tension filament is then manipulated toapply a force to the implanted anchors and modify the shape of the valveannulus (Block 1440). Once a desire degree of modification has beenachieved, a locking device is placed on the tension filament to securethe tensioning device (Block 1450). Method 1400 ends at Block 1460.

While various embodiments according to the present invention have beendescribed above, it should be understood that they have been presentedby way of illustration and example only, and not limitation. It will beapparent to persons skilled in the relevant art that various changes inform and detail can be made therein without departing from the spiritand scope of the invention. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the appendedclaims and their equivalents. It will also be understood that eachfeature of each embodiment discussed herein, and of each reference citedherein, can be used in combination with the features of any otherembodiment. All patents and publications discussed herein areincorporated by reference herein in their entirety.

1. A system for altering a mitral valve annulus comprising: an elongatedtension member having a first end and a second end; a plurality ofhelical anchors, each helical anchor having a coil, and a distal end anda proximal end, the distal end of each helical anchor having a sharpenedtip portion, and the coils of the helical anchors defining an innerchannel through the center of the coils along a length of the helicalanchors; and at least one elongated tubular delivery member having adistal end, a proximal end, and a lumen communicating along the lengthof the tubular delivery member; wherein when the system is deliveredproximate a mitral valve annulus, the anchors are deployed on theanterior and posterior portions of the annulus, and the elongatedtension member is routed through the inner channel of the helicalanchors by alternating from a helical anchor on the anterior orposterior side of the annulus to an anchor on the opposite side of theannulus such that the elongated tension member crosses the mitral valveeach time it is routed through a helical anchor subsequent to theprevious helical anchor that the elongated tension member is routedthrough.
 2. The system of claim 1 further comprising at least onelocking device disposed on a first end of the elongated tension memberadjacent one of the plurality of helical anchors.
 3. The system of claim2 wherein the at least one locking device comprises a lock member havinga lock member lumen and a stop member having a stop member lumen sizedto receive the lock member in a locking configuration about theelongated tension member disposed within the lock member lumen, the atleast one locking device sized such that is cannot pass through an innerchannel of an adjacent helical anchor.
 4. The system of claim 1 whereinthe elongated tension member comprises at least two trans-leafletportions, each trans-leaflet portion extending between a first helicalanchor implanted in an anterior valve annulus and a second helicalanchor implanted in a posterior valve annulus.
 5. The system of claim 4wherein the plurality of helical anchor comprises five helical anchorsand wherein the elongated tension member comprises four trans-leafletportions, the trans-leaflet portions extending across the valve in azig-zag configuration.
 6. The system of claim 4 wherein the plurality ofhelical anchor comprises three helical anchors and wherein the elongatedtension member comprises two trans-leaflet portions.
 7. The system ofclaim 1 wherein the at least one elongated tubular delivery memberincludes an elongated helical anchor driver having a distal opening forreceiving a proximal end of the helical anchor.
 8. The system of claim 1wherein each of the plurality of helical anchors is configured tocorrespond to a portion of the valve annulus.
 9. The system of claim 1wherein the delivery member further comprises an anchor guide, whereinthe shape of the anchor guide corresponds to a radius of at least aportion of the valve annulus.
 10. A method of treating mitral valveregurgitation, the method comprising: providing a tensioning deviceincluding a plurality of anchors, and a tension filament; preloading thetensioning device into a delivery member; delivering the tensioningdevice to a location adjacent a mitral valve annulus; implanting theanchors into the annulus; applying a tension force to the tensionfilament; altering the shape of the annulus in response to applicationof the tension force; and securing the tensioning device on the valvesuch that there is tension on the tension filament.
 11. The method ofclaim 10 furthering comprising adjusting the tensioning filament so thatforce vectors are exerted on the mitral valve annulus and the shape ofthe mitral annulus is changed.
 12. The method of claim 11 whereinreshaping the valve annulus reduces mitral valve regurgitation.
 13. Themethod of claim 10 wherein implanting the anchors into the annuluscomprises sequentially alternating the implantation of the plurality ofhelical anchors between an anterior valve annulus and a posterior valveannulus.
 14. The method of claim 13 wherein the tensioning filament isdelivered in a trans-leaflet configuration across the valve.
 15. Themethod of claim 10 wherein the tensioning device comprises five helicalanchors and a tensioning filament having a plurality of trans-leafletportions, wherein each trans-leaflet portion extends between ananteriorly implanted helical anchor and a posteriorly implanted helicalanchor.
 16. The method of claim 10 wherein securing the tensioningdevice comprises placing at least one locking device on an end of thetensioning filament adjacent a helical anchor